| 摘要 |
The subject of the invention is a pipette which comprises a frame portion (1) shaped as a handle, a cylinder being formed inside the frame portion (1), as well as a piston (5) fitted into the cylinder by means of a seal ring (7), a piston rod (4) connected to the piston (3), as well as a press knob (5) with shaft (6), fitted at the upper end of the frame portion (1). Around the shaft (6) of the press knob (5), a calibration sleeve (9) is fitted by means of a threaded joint (8), by means of which calibration sleeve (9) the lower limit of the movement of the piston (3) during pipetting can be determined. According to the invention, the calibration sleeve (9), as surrounded by the mantle (10) of the hollow press knob (5) and by the upper part of the pipette frame (1), is placed at a distance both from the mantle (10) of the press knob (5) and from the inner face of the cover of the upper part of the pipette frame (1). Thereby the hollow press knob (5) and the pipette frame (1) form a cover protecting from conducted heat and allow a space of air around the adjustment and calibration sleeve (9).
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